Study of the Behaviour of S355 Welded Joints with CHS Columns and Through Beams

Circular hollow section elements are an appealing solution in steel structures, but the complexity in the realization of the joints represents their main limitation, particularly in the case of columns with passing through beams. In this context laser cutting technology allows for simplified solutions. The minimal clearances between the elements and bevels to achieve full/partial penetration butt welds are important aspects to optimize the behaviour of joints subjected to seismic and gravitational loads. The RFCS LASTTS project was conceived and funded to investigate the performance and to optimize the fabrication of the joints. In this context, numerical analyses based on the FE method by means of the ABAQUS software and an experimental tensile tests campaign on the joints were carried out. Three different welding solutions of joints, full penetration butt weld and full/partial fillet weld, made using mild steel S355 are studied. The study provides important indications on the choice of the most suitable weld techniques for the studied joints highlighting a good behaviour of the full‐strength fillet weld solution. Moreover, the good agreement between experimental and numerical results highlights the capability of the model to investigate joint with different geometries.